Weird allergic reaction! Causes? Treatment? Next Steps?

My wife had what the doctor diagnosed as an “allergic reaction” around two weeks ago. Her lip got puffy on one side and then eventually her whole face. This happened while she was at work and it was decided that it must’ve been something that she came in contact with at work. She also had been exhibiting patches of dry skin on her face, seemingly making her more susceptible to irritation.

She was given a basic antibiotic and steroid; which ran out three or four days ago from today (10/9) we were previously living in a house that had lots of left over pet smells/hair/dander and thought that could be the reason, so we washed our bedding. Last night she started experiencing the same symptoms again, I gave her benedryl and cortizone cream, and now this morning it is getting progressively worse. Last night we used the freshly washed bedding, but I did add one blanket that was used at the old house and has not been washed. We were also house sitting for my parents the last time it happened and they have a dog that sheds a lot and is allowed on all the furniture. We were at my parents house last night laying on the dog hair covered furniture.

My question is this: which is more likely to cause an allergic reaction; contaminants in the bedding from sleeping in a house with residual dog aggravators? or being in a house with an actively shedding dog? Keep in mind we are assuming that dog something is the culprit, and she has never had any reactions like this before; but then again, she has never been exposed to an actively shedding dog for any significant length of time before either.

Any ideas/advice/suggestions/requests for more info are greatly appreciated. She is going to a health clinic right now.